An axial gas turbine engine, such as an aircraft “jet-engine,” generally comprises an air inlet, a compressor section, a fuel combustion chamber, a turbine section, one or several rotatable drive shafts connecting corresponding compressors and turbines, an exhaust outlet, and structures for supporting the drive shafts and for mounting the engine to, e.g., an aircraft.
Typically, the supporting structures are static parts that include an inner shell or ring, for connection to bearings and a centrally located drive shaft, and an outer shell or ring, for connection to, e.g., an engine casing, and where circumferentially distributed struts extend between and connect the inner and outer shells/rings. The supporting structures are designed to be capable of transferring loads between the drive shaft and the engine casing. An axial gas flow through the engine is allowed to flow between the struts which normally are aerodynamically designed. Supporting structures of the type discussed here are exposed to rather extreme balance loads and thermally generated loads.
Traditionally, supporting structures have been manufactured as one large casted component. To reduce costs, it has over the recent years become more common to manufacture supporting structures by assembling of prefabricated parts, such as smaller casted, forged and sheet metal parts. Typically, the parts are welded together. A problem related to this technique is the heat induced into the component during the welding process. This heat leads to distortions in the final product and a non-exact geometry of individual parts. As a result, time must be spent on measurements and manual adjustments. Therefore, assembling of prefabricated parts is often difficult to automate in an efficient way.
There is a need for methods of manufacturing supporting structures of the above type that both are cost-effective and allow for efficient automation.